On 19/07/2024 01:19, Mayank Rana wrote: > Hi Krzysztof > > On 7/17/2024 11:05 PM, Krzysztof Kozlowski wrote: >> On 17/07/2024 19:20, Mayank Rana wrote: >>> Hi Krzysztof >>> >>> On 7/16/2024 11:47 PM, Krzysztof Kozlowski wrote: >>>> On 17/07/2024 00:09, Mayank Rana wrote: >>>>> Hi Krzysztof >>>>> >>>>> On 7/16/2024 12:28 AM, Krzysztof Kozlowski wrote: >>>>>> On 15/07/2024 20:13, Mayank Rana wrote: >>>>>>> To support MSI functionality using Synopsys DesignWare PCIe controller >>>>>>> based MSI controller with ECAM driver, add "snps,dw-pcie-ecam-msi >>>>>>> compatible binding which uses provided SPIs to support MSI functionality. >>>>>> >>>>>> To support MSI, you add MSI support... That's a tautology. Describe >>>>>> hardware instead. >>>>> Ok. let me repharse it to provide more useful information. >>>>>>> >>>>>>> Signed-off-by: Mayank Rana <quic_mrana@xxxxxxxxxxx> >>>>>>> --- >>>>>>> .../devicetree/bindings/pci/host-generic-pci.yaml | 57 ++++++++++++++++++++++ >>>>>>> 1 file changed, 57 insertions(+) >>>>>>> >>>>>>> diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.yaml b/Documentation/devicetree/bindings/pci/host-generic-pci.yaml >>>>>>> index 9c714fa..9e860d5 100644 >>>>>>> --- a/Documentation/devicetree/bindings/pci/host-generic-pci.yaml >>>>>>> +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.yaml >>>>>>> @@ -81,6 +81,12 @@ properties: >>>>>>> - marvell,armada8k-pcie-ecam >>>>>>> - socionext,synquacer-pcie-ecam >>>>>>> - const: snps,dw-pcie-ecam >>>>>>> + - description: | >>>>>>> + Firmware is configuring Synopsys DesignWare PCIe controller in RC mode with >>>>>>> + ECAM compatible fashion. To use MSI controller of Synopsys DesignWare PCIe >>>>>>> + controller for MSI functionality, this compatible is used. >>>>>>> + items: >>>>>>> + - const: snps,dw-pcie-ecam-msi >>>>>> >>>>>> MSI is already present in the binding, isn't it? >>>>> It is mentioning as msi-parent usage which could be different MSI >>>>> controller (GIC or vendor specific one) not related to designware PCIe >>>>> controller based MSI controller. >>>>> >>>>>> Anyway, aren't you >>>>>> forgetting specific compatible? Please open your internal (quite >>>>>> comprehensive) guideline on bindings and DTS. >>>>> Here I am trying to define Designware based PCIe ECAM controller >>>>> supporting MSIcontroller based device. Hence I am not mentioning vendor >>>>> specific compatible usage >>>>> and keeping generic compatible binding for such device. >>>> >>>> I know what you try, yet it feels simply wrong. Read your guideline. >>>> Are you sure you work on Designware core itself, not on one used in >>>> Qualcomm? I would expect people from Designware to design Designware >>>> cores and people from Qualcomm only to design licensed cores. >>> Ok. let me not make generic comment here. I refereed how it is done with >>> other >>> snps based IP usage for example USB, and would follow same. >> >> Well, it is not. If you read their bindings or any reviews related to >> such cores, you would see that single Designware compatible is always >> never appropriate. Such cores always have customization per user. >> >> You can also look at the binding you are changing. Do you see Designware >> alone? No. > I found reference in this binding as below: > 79 items: > 80 - enum: > 81 - marvell,armada8k-pcie-ecam > 82 - socionext,synquacer-pcie-ecam > 83 - const: snps,dw-pcie-ecam > > And as you mentioned in previous emails about how to add such usage, I > ACKed it but let me put reason why I tried to add differently to start > with it. > > This specific driver under-discussion is really not vendor specific > driver. It can work with any PCIe controller which is already configured > in ECAM mode by firmware (i.e. PCIe controller from SNPS or any other > vendor). There are few quirks only added to get specific vendor based > SOC configuration for SNPS PCIe controller by different SOC vendors. > > 90 - description: > 91 CAM or ECAM compliant PCI host controllers without any quirks > 92 enum: > 93 - pci-host-cam-generic > 94 - pci-host-ecam-generic > > Above enum based usage works for SA8775P platform which is having SNPS > PCIe controller which doesn't need any quirks, and firmware is able to > configure PCIe controller into ECAM mode. Here I tried adding PCIe SNPS > controller based MSI support as SA8775P doesn't support LPI/ITS for MSI. > I need to differentiate it hence added generic enum as MSI controller is > part of SNPS PCIe controller, and not separate MSI IP here. Although how > many MSI can be supported it depends on how many SPIs are available/used > with MSI controller depend on particular SOC. Hence put as > snps,dw-pcie-ecam-msi as usage and variable number of MSI. hopefully I > am able to convey why this driver binding modified differently. Your binding already defines some specifics for specific device, but you still claim all of them are identical. Sorry, I am confused. Read carefully writing bindings, consult internal guideline (go/upstream - it is really detailed!) and then come with a solution. Best regards, Krzysztof
